The OSUCCC Genotyping and Sequencing Shared Resource (GSSR) - first established in 1997 as a restricted developing shared resource - has rapidly evolved into a state-of-the art DNA analysis facility providing an essential service available to and requested by the OSUCCC membership. The GSSR has demonstrated ability to handle large sequencing volumes, maintain high service quality, and accommodate a steadily increasing number of users. The GSSR has leveraged strong institutional support and user fees totaling $4.4 M to provide sequencing and genotyping performed by highly experienced personnel with outstanding quality control. The GSSR is located on the fourth floor of the Tzagournis Medical Research Facility with three other CCC SRs. The GSSR has one 48 capillary Applied Biosystems 3730 DNA Analyzer, one 96 capillary ABI PRISM[unreadable] 3700 DNA Analyzer (to be replaced by an ABI 3730 in early 2004) and ancillary equipment for DNA sequencing and genotyping preparation. Now as a full SR, the GSSR has assumed a leading role in supporting molecular cancer research with state-of-the-art equipment, as well as developing novel methodologies that will become essential tools in the coming years for our membership. Specific goals for the sequencing and genotyping core are: (1) To provide affordable, high-throughput, high-quality genotyping and sequencing services in a timely manner. Genotyping will include screening methods for finding new polymorphisms (such as DHPLC) and scoring known polymorphisms. (2) To develop novel methodologies and applications relevant to cancer research, including genome-wide analys s of DNA methylation, gene silencing, and gene dosage, and large-scale genotyping panels (including haplotyping) targeted to cancer biology and therapeutics. (3) To train researchers and students in software utilization, data interpretation, and experimental strategies, conduct trouble shooting meetings with laboratory groups, and assist in the preparation of materials for publication. In the past year, usage of GSSR has increased 12% with now nearly 40 members from 3 CCC programs using the facility. The GSSR work has supported over 350 peer-reviewed publications (excluding reviews) since the last competitive renewal. Of these, 67 (19%) were in the 17 journals ranked highest by citation index (10-29.6). Building on this solid foundation, the task of the OSUCCC GSSR is to be an outstanding resource in the application of DNA analysis, in an era of rapid and profound technological advances.